Fluid cooled systems may use a phase change of a fluid to move heat from one location or object to another. As a liquid becomes a gas, it absorbs heat energy. The gas may then be exhausted to a heat exchanger, where the gas is condensed to liquid form and heat is removed. The liquid may then be returned to the area from which heat is to be extracted.
In specialized fluid cooled systems, such as spray cooling of an electronic system adapted for attitude independent applications in avionics, it may be possible to passively remove fluid from an enclosure of the electronic system. Such passive fluid recovery systems have many advantages, such as elimination of complex valve systems that are present in active fluid recovery systems. However, during operation of a passive fluid recovery system, a mixture of gas and liquid is removed from the enclosure.
This mixture of gas and liquid may present difficulties within a passive fluid recovery system. For example, during a start-up of the system, it may be difficult to pump the mixture. Even when the fluid at a pump inlet is substantially liquid, operation of the pump may lower pressure sufficiently to introduce a vapor component to the fluid. Such vapor may cause failure and/or reduced effectiveness of the pump. Accordingly, advancements in pumping systems would be welcome.